Thin film magnetic disc media are typically lubricated with a perfluoropolyether coating to reduce wear during the lifetime of the discs. Conventionally, a thin lubricant film is applied to the disc surface by dipping the disc into a bath containing a small amount of lubricant, e.g., typically less than about 1% by weight of a perfluoro- or hydrocarbon compound dissolved in a solvent. However, a drawback inherent in this process is the consumption of large quantities of solvent, resulting in increased cost and concern with environmental hazards associated with the presence of solvent vapors in the workplace.
Another drawback attendant upon dip lubrication is the non-selectivity of the method, in that lubricant is applied to the entire disc surface. In some instances, e.g., with zone-textured media having a specific radial band designated for the landing and take-off zone of the read-write head, the lubricant film present on the other portions of the disc surface is unnecessary, wasteful and, in some cases, detrimental to the performance of the head-disc interface.
Yet another drawback associated with the conventional dipping methodology stems from the use of mixtures of long chain polymers having a wide distribution of molecular weights. It is known that the molecular weight of the lubricant has an effect on the mechanical performance of the head-disc interface. In conventional practice, the polymeric lubricant mixtures must be subjected to fractionation before adding the lubricant to the solvent to obtain a fraction having a desired molecular weight distribution, thus adding an additional step and increasing the cost of the process.
Accordingly, there exists a need for technology enabling the application of a lubricant film free of the aforementioned drawbacks of conventional dipping.